Gas turbine blade
AssigneeSiemens Aktiengesellschaft
InventorsRobert Fleck, Thomas Jansing, Eckart Schumann
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Abstract
Disclosed is a gas turbine blade (1) having a ceramic heat-insulating layer (17). The ceramic heat-insulating layer (17) consists of 10-95% wt. % magnesium aluminate, 5-90 wt. % magnesium oxide and 0-20 wt. % aluminum oxide. Magnesium oxide particles are incorporated into a matrix made of spindle-shaped magnesium aluminate, enabling the thermal expansion coefficient of the ceramic heat-insulating layer (17) to be adapted in a particularly suitable manner to a metallic base body (15) of the gas turbine blade (1). The ceramic heat-insulating layer (17) also has a porosity which is greater that 3 vol. %, thereby guaranteeing sufficiently low heat conductivity.
Claims20
A gas turbine blade with a ceramic thermal insulation layer that comprises 10 to 95 percent by weight magnesium aluminate (MgAl2O4), 5 to 90 percent by weight magnesium oxide (MgO), 0 to 20 percent by weight aluminum oxide (Al2O3) as well as a residue of ordinary impurities and is embedded in the granules of magnesium oxide (MgO) with an average diameter of 0.1 μm to 10 μm in a matrix of spinel-shaped magnesium aluminate (MgAl2O4), whereby the ceramic thermal insulation layer has a porosity exceeding 3 percent by volume.
A gas turbine blade having a body comprising a nickel or cobalt base superalloy and a ceramic thermal insulation layer applied to the body, comprising:
- a first layer applied adjacent the body, the first layer comprising:
- 10 to 95 percent by weight magnesium aluminate (MgAl2O4),
- 5 to 90 percent by weight of magnesium oxide (MgO),
- 0 to 20 percent by weight aluminum oxide (Al2O3), wherein
- the magnesium oxide is in a granule form with an average diameter of 0.1 μm to 10 μm and the magnesium oxide granules are disposed in a matrix of spinel-shaped magnesium aluminate;
- and
- a second layer differing in composition from the first layer applied to the first layer.
A ceramic insulation layer of a turbine blade having porosity exceeding 3 percent by volume, comprising:
- 10 to 95 percent by weight magnesium aluminate (MgAl2O4);
- 5 to 90 percent by weight magnesium oxide (MgO);
- 0 to 20 percent by weight aluminum oxide (Al2O3);
- and
- a residue of ordinary impurities,
- whereby the magnesium oxide (MgO) has an average diameter of 0.1 μm to 10 μm and is arranged in a matrix of spinel-shaped magnesium aluminate (MgAl2O4).
Dependencies are inferred from the claim text.